Harmonic compressor



` sept-15,. 193s.

l.,l. B. REPLOGLE HARMONI C YICOMPRES soR Filed-May 31, 1952 2Sheets-Sheet 1 :1L/MIM,

' J. B. REPLoGl- E sept. 15, 1.936. 2,054,097

Y HARMONIC COMPRESSOR l Filed May 31, 1932 2 sheetsneet 2 /mA C 60 c; re

Patented Sept. 15, 1936 UNITED sTATEs` PATENT OFFICE The inventionrelates to electrically driven reciprocating apparatus and moreparticularly to compressors such, for example, as are adapted for therefrigeration industry.

One of the primary objects of the invention` is to produce anelectrically operated reciprocating device free from rotatingparts inwhich the electrical energy is converted directly into the energy ofmechanical reciprocation.

Another important object of the invention is to obtain a compressor ofsimple design adapted to be produced at low initial cost and to operateat high efliciency.

Other objects will be more apparent upon the consid-eration of thedetails of construction hereinafter set forth and illustrated in theaccompanying drawings, wherein Figure 1 is a side elevation partly insection of an electrical compressor in which the piston of each powerunit is shown at the end of its compression stroke;

Figure 2 is an end view of a power ,unit with the cap 21 and spring 22removed; ,Y

Figure 3 is a transverse section through a power unit on the line 3-3 ofFigure l;

Figure 4 is an electrical diagram;

Figure 5 is a sectional elevation of one unit showing the pistonstarting on the backwardV or intake stroke;

Figure 6 is an enlarged view of a portion of the cylinder and pistonshown in Figure 5;

Figure '7 is an enlarged longitudinal section through the electricvibrator 2Q.

The apparatus comprises a base A on which are symmetrically mounted twopower units B and C, respectively, connected by an intermediatecompressor chamber D. Each of the power units B and C contains areciprocable element, and the arrangement is such that the movements ofthe elements are always equal and in opposite directions. Thereciprocable element in the particular construction illustr-ated is acylindrical piston Ill adapted for horizontal movements in a surroundingcylinder I I. The cylinder is arranged centrally of a magnetic housingI2 which has an annular slot I3 therein arranged between the centralcore I4 and the surrounding wall I5. Within the annular recess isarranged a magnetizing coil I6 which when energized induces a magneticfiel-d in the housing I2. At the open end of the housing there ispreferably arranged an annular pole piece I'I projecting inwardly fromthe outer wall I5 and forming an annular passage I8 in which themagnetic field is concentrated.

The motive powerV for the device is obtained by placing in the annularspace I8 an electric vibrator 2@ consisting of a coiled conductor'through which alternating current is caused to flow. This vibrator issecured to the recipro-Y cable piston IB through the medium of a spidermember 2l. The vibrator is also disposedbetween two coiled springs 22and 23 adapted to normally maintain the vibrator in a central po`si tionwithin the magnetic eld.

With the arrangement thus far described,

whenever an alternating current of .predetermined frequency is passedthrough the coil of the vibrator 2B forces are set up in the vibratortending `to move the vibrator relative vto theV housing alternately inopposite directions jfor each alternation ofthe electric current. It is`an essential feature of my invention that the re'- siliency of thesprings 22 and 23 be so propor-` tioned to the mass of the vibratingelement that the natural period of vibration of this element correspondsto the frequency of the alternating` current. In other words, assumingthat a 60. cycle alternating current is impressed on the coil of thevibrator, it is necessary then that the vibration period of the VibratorZilQthe piston II) and the parts connected thereto Ybe exactly 60 cyclesper secon-d. With this condition of tuning between the mechanicalvibrationl period of the vibrator and the electrical frequency of thecurrent, the amplitude of-Vibration of the vibrator will be built up toan appreciable value determined by the electrical characteristics of thevibrator and the device becomes a reciprocating electric motorvibratingV with true harmonic motion.

As heretofore set forth, there are two power units B and C and Veach of`these units contains identical parts, the arrangement'being such thatelectric current in any given instant flows oppositely throughthevibratorswith respect4 to the magnetism in the respective units. Thusthe mechanical movements of the vibrating elements are always inopposite directions and by having identical units B and C the powerimpulses are exactly equal in the opposite directions. This arrangementplaces the device in balance and eliminates vibration of the machine asawhole.

My invention may be embodied in Yvarious specic constructionsdependingfupon the V'character of the work to be performed by thedevice, but I will now describe more vin detail a preferred constructionas illustratedin the drawings.`

The piston I 0 has a longitudinal passageway 25 extending completelythrough Vthe same ,commu- V'gio the housing I2 for this purpose.

ing portion 46 of the cylinder Il.

Vprovided with a central aperture 4I and is arranged in its entiretywithin the compressionV nicating at the outer end with the chamber 26formed within the cap 21. The chamber 26 is in open communication withthe sump 28 in the base A, there being a radial port opening 29V in Atthe inner end of the hollow piston I Vthere is a disk valve 30 whichseats against the end face 3l of the piston.

The disk 3U is preferably of polygonal shape andV of a size to t withinthe f cylinder II and be guided` thereby. The flat portions 32 of thedisk provide the necessary clearance for permitting the escape of uidpast the valve.Y The valve is assembled to the piston by. means of alink V33 fastened at one end to the center of the disk valve and at theother end to a pin V34 in the piston. The link forms a lost motionconnection which, as shown, is due to the looping of the link over thepin with a slight clearance.` The cylinder II is formed with an endshoulder 35 against which a diskV Valve 36 normally rests. This valve asshown has an out-turned annular ange 3'! for guiding the valve spring 38which in turn is held in position by the cap 39 threaded to the project-The cap is Y p chamber D.

V30 with a Venturi portion 42.

' in'cornmunication withthe downwardly extend-V The central passage 25in the piston is provided radial bores 43 leading outwardly fromthethroat of the venturi to an annular recess 44 on the outer surfacesof the piston. VThis recess is at all times ing passage 45 in thehousing from which a'tube 46 leads to the bottom of the sump 28. 41represents the inlet port to the sump and 48 represents the outlet fromthe compression chamber D. As shown, this chamber has radial flanges 49for dissipating the heat'of compression.

The compressor may be used with any suitable medium but where it is tobe used for a refriger- Y Vating apparatus afdesirable refrigerant ismethyl chloride.

The inlet 41 isconnected to the low pressure side of the refrigeratingapparatus and the outlet 48 to the high pressure side. The methylchloride and lubricant are returned to the sump 28 through the inlet 41and the lubricant settles tothe bottom of the Vsump while the `Y methylchloride gas fills the balance of the sump and circulates into each ofthe units B and C through the radial passages 29, annular recesses I3Yand outer chambers 26. During the reciprocation of the piston I8 the gasinthe cylinder II between the valves 3|! and 36 is compressed by theinward movement of the piston and escapes into theY compressionV chamberD. YIn the outward stroke of the piston the gas is drawn through theY3l! into the space between said valve and the check valve 36. Theaspirating effect of the venturi causes lubricantto be drawn into theventuri from the sump 28 and mixwith the refrigerant. Thus thereciprocation of the piston I0 builds up a pressure within the chamberD.

Figure 4 shows an electrical diagram of the preferred circuits inwhich50 represents a transformer having a primaryl adapted to operateon'theV ordinary linevoltage such, for example, as 110 volts 60 cycle A.C. The secondary 52 of the transformer is adapted to deliver'the desiredvoltage for any particular construction and in the example illustratedis wound to deliver 62/3 volts. The Vibrator coils 28h and 29o areyconnected in series with the secondary 52 while the center tap 54 of thetransformer is grounded and. connected The piston also has intermediatethe coils 20b and 20c. In order to obtain a constant magnetic eld forthe field coils I6b and |60 a rectifier 55 is connected to the sec Yondary and this in turn is connected through the coils I6b and |6c tothe grounded center tap 54 in such a wayA as to produce oppositemagnetic effects. Y

For convenience in passing the current through the coils 20 of theapparatus illustrated in Figure 1 the cap 21 of each power unit isconnected to but insulated from the housing I5.: 'Ihis is accomplishedby inserting insulation 56 between the Vflanges 51 and 58 which in turnarersecured tothat the outer casing I2 has a conical inner suri face 6Iin which is seated the correspondingly shaped end of the core I4. Thecylinder. II has an annular flange 62 thereon adapted to abut` the outerface of the housing ,I 2 and has a threadi ed portion'63 for-engagingtheV core I4, thus clamping the core and housing together and forming acomposite structure. The cuter end of the core I4 is provided with aseries of slots 64 for receiving the arms 65 of the spider 2I. ThisYspider has a Vhub 66 secured to the outer end of the piston 25 andclamped against a shoulder 61 by the clamping nut 68 threaded on thepiston. The spider arms are connected by a continuous ring 69 forming anabutment for the inward end of the conducting coil 10. YThis coilpreferably consists of a continuous helix of copper or other suitableconductor, the leaves of which are substantially rectangular in crosssection. Between the adjacent convolutions of the helical conductor areinserted steel washers 1I split on one radius to permit following thecontour of the helix. These washers are insulated from the copper helixby identical washers Y12 made of insulating material, the steel andinsulating washers having an inner diameter such as to bear Von theedges of the spider arms. In order to secure the helix and intermediatewashers in one compact Yunit a series of bolts 13 (preferably three innumber as shown) are inserted through coincident perforaf tions Vin 'theconvolutions. Each bolt 'is insulated from the convolutions byraninsulating tube v16. The head 14 of the bolt is inserted in a recess inthe flange 69 and insulated therefrom by a suitable washer 15. 11 is aclamping ring to which the bolts 13 are threadedly secured, therebyclamping the helix and intermediate washers into a compact unit. Thering has an annular flange 18 projecting into the inner end of the coilspring 22. It will be observed that the helical coil has one end thereofelectrically contacting with the clamping ring 11 and the otherelectrically contacting with the flange 69 of the spider member. Theelectric circuit is from the cap 21 through coil spring 22,7clamplngring 11, helical coil 19, flange 69 and coil spring 23 to the housing I2which acts as a ground and is suitably connected to the grounded centertap ofthe secondary coil of the transformer. Thus the coil springspservenot only to introduce the required resiliency to mechanically tune theapparatus to the frequency of the alternations but also serve to conductthe alternating current to the reciprocating helical coil 1D. Thesprings 22 and 23 are always under compression so as to be always heldby continuous compression against the insulated surface 21 and thegrounded surface of the frame l2 so as to have sufficient pressure tocomplete the electric circuit through the springs 22 and 23 and thehelical conductor 10 at all times. These springs therefore always havenon-reversible stresses. In other words, these springs are neversubjected to a reverse stress when the device is in operation.

From the foregoing description it will be observed that I have providedan improved form of harmonic compressor which is entirely free fromrotating parts and is operable from an ordinary alternating currentsupply line. While I have described the apparatus in considerabledetail, it is to be understood that the invention is capable of beingembodied in various other forms.

What I claim as my invention is:

l. 'Ihe combination of a magnetic field element, an element in the fieldfor carrying alternating current, one of said elements being fixed andthe other being movable with respect thereto, an oppositely actingalternating current supply of predetermined frequency connected to thesecond element and constituting the sole actuating current of the deviceand resilient means interposed between said movable amd fixed elementsat separated po-ints and having a predetermined resiliency adapted toimpart to said movable element a natural period of vibrationcorresponding to th frequency of the alternating current.

2. The combination of a magnetic field element, an element in the iieldfor carrying alternating current, one of said elements being xed and theother being movable with respect thereto, an oppositely actingalternating current supply of predetermined frequency connected to thesecond element and resilient means interposed between said movable andfixed elements at separated points and having a predetermined resiliencyadapted to impart to said movable element a natural period of vibrationcorresponding to the frequency of the alternating current and acompressor mechanically connected to said movable element.

3. An alternating current electrically operated pumping apparatuscomprising a cylinder, a piston reciprocable therein, valves for feedinguid to said cylinder, a helical coil coaxial with said piston, means forpassing an alternating current of predetermined frequency through saidcoil, means for producing a substantially constant magnetic field aroundsaid coil and means mechanically connected to said coil for producing apredetermined resiliency adapted to impart to said movable element anatural period of vibration corresponding to the frequency of thealternating current.

4. An alternating current electrically operated pumping apparatuscomprising a magnetic housing having an annular gap, a helical coilmounted for reciprocation v'ithin said annular gap, means for energizingsaid coil with alternating current of predetermined frequency, a coaxialpiston connected to said coil to reciprocate therewith, a cylinder forsaid piston, springs on opposite sides of said coil, the mass of saidreciprocating parts being so proportioned with respect to the resiliencyof said springs as to impart a natural period of vibration correspondingto the frequency of the alternating current.

5. Electrically operated pumping apparatus comprising a pair of coaxialreciprocating compressors, and separate means for electricallyreciprocating the respective compressors always in opposite directions.

6. Electrically operated pumping apparatus comprising a pair of coaxialreciprocating compressors, resilient means connected to each of saidcompressors adapted to impart thereto a predetermined natural vibrationperiod, and electrical means for urging the respective compressorsalways in opposite directions in synchronism with said natural vibrationperiod.

7. In an apparatus of the class described, outer and inner magnetic polepieces having an annular gap therebetween, a vibrator mounted forreciprocation in said annular gap comprising a helical conductor, andmagnetic members interposed between the adjacent convolutions of saidhelical conductor.

8. Electrically operated pumping apparatus comprising a compressionchamber, a pair of coaxial cylinders communicating with said compressionchamber, pistons in each of said cylinders, an annular vibratorconnected to each of said pistons, a magnetic housing surrounding eachcylinder and having an annular gap embracing said vibrator, amagnetizing coil for the magnetic housing, resilient means connected toopposite ends of said vibrator and adapted to impart a natural vibrationperiod to said vibrator corresponding to the frequency of alternatingcurrent, an electric coil in said vibrator and means for passingalternating current through said coil, the helical coil being sodisposed with respect to the magnetic field in the correspondingmagnetic housing that each of said vibrators is urged always in theopposite direction from the other vibrator.

9. Electrically operated pumping apparatus, comprising two coaxiallyreciprocating compressor members of substantially equal mass, separatemeans for simultaneously reciprocating them in opposite directions atsubstantially the same speed.

10. Electrically operated pumping apparatus comprising two coaxiallyreciprocating compressor members, separate actuating means forreciprocating them in opposite directions at substantially the samespeed, and a compression chamber located intermediate the compressormembers actuating means into which the material acted upon is dischargedby the compressor members.

11. Electrically operated pumping apparatus comprising a reciprocatingpumping element, electric means for reciprocating said pumping element,a spring associated with said reciprocating pumping element forelastically resisting the reciprocating movement of said element, saidspring being under compression Vat all times during the reciprocation ofsaid pumping element, so that it is never subjected to reverse stresswhen the apparatus is in operation.

12. Electrically operated pumping apparatus comprising a reciprocatingpumping element, electric means for reciprocating said pumping element,a spring associated with said reciprocating pumping element forelastically resisting the reciprocating movement of said element, meansfor preventing a reversal of stress in said spring when the apparatus isin operation.

JAMES B. REPLOGLE.

